Grinding mills are one form of apparatus used for processing materials as described above. Typically grinding mills generally comprise a drum shaped shell mounted for rotation about its central axis. The axis of the shell is generally horizontally disposed or slightly inclined towards one end. The interior of the shell forms a treatment chamber into which the material to be processed is fed.
In one form of milling known as SAG (semi autogenous grinding), a grinding medium such as balls or rods is fed to the treatment chamber with the material to be processed and the shell rotates. During rotation of the shell the grinding medium acts on the material to cause the crushing or grinding action. The grinding medium and material to be processed are carried up the side of the shell as a result of the rotation of the shell whereafter it falls towards the bottom of the shell under the influence of gravity.
The inside surfaces of the mill are typically protected by an arrangement of wear components collectively referred to as a mill liner. The mill liner usually includes lifter bars spaced around the inner circumference of the mill. The lifter bars assist in lifting the charge inside the mill up the side of the shell as the shell rotates. Further, the mill liner often includes wear plates which are provided in between each lifter bar. The lifter bars or wear plates may be formed as a resilient body, with a number of wear resistant inserts embedded in the resilient material. The inserts are produced by casting of molten metals in a mould.
Over time, the components of the mill liner wear away and require replacement. This necessitates that the mill be stopped for a period of time which causes the cessation of the grinding of material, and may also necessitate the shutting down of other machinery in a plant which works on the material produced by the mill. There is a continued need to provide mill liner components with improved longer service lives to reduce the mill stoppage time.